This invention relates to computer systems, and more specifically, the design and layout of components of computer systems.
With the growth of computing applications, there has been an associated increase in the need for servers and larger scale computer systems. These server systems include such components as CPUs, hard drives, CD-ROMs, DVDs, tape backup systems, peripheral cards, monitors, and universal power supplies. Network servers require a significant amount of storage capacity, typically in the form of hard disk drives. A single server may use many hard disk drives to increase the total storage capacity, or, in an arrangement known as a Redundant Array of Inexpensive Disks (xe2x80x9cRAIDxe2x80x9d), to provide secure data redundancy. In a RAID system, if one hard drive fails, information in the other drives is used to recover the lost data. Some RAID systems provide for xe2x80x9chot swapping,xe2x80x9d in which a failed hard drive can be replaced and the lost data reconstructed from the remaining drives without powering down the system.
xe2x80x9cHot swapxe2x80x9d drives include several characteristics not normally required by conventional PC hard drives. xe2x80x9cHot swapxe2x80x9d drives require greater accessibility than conventional drives, which are typically mounted in the computer chassis and attached to an internal hard drive bay. It is desirable to place the xe2x80x9chot swapxe2x80x9d drives in easily accessible bays, mounted such that they are readily removable without having to open the computer case. It is additionally desirable that the drives be capable of making proper electrical connections with the network computer when being replaced. When the interface connectors on the hard drive are not properly mated to their corresponding connectors, connector pin damage or failures caused by intermittent breaks in the electrical transmissions between the computer and the drive may result.
The various server components can be mounted vertically on a server rack or cabinet in a dedicated server location, often with temperature, humidity, and particle controls. Using such racks, server components can be stored with high space efficiency, while allowing easy visual and manual access. Server racks and cabinets have standard size mounting holes to which computer equipment can be attached. Rack-mounted equipment are typically provided in xe2x80x9cUxe2x80x9d sizes. A 1U sized component measures 1.75xe2x80x3 high, 19.00xe2x80x3 wide, and 20.00xe2x80x3 deep, while a 2U sized component is 3.5xe2x80x3 high. These slim form factors allow a larger number of devices to be mounted on a given rack. However, these slim cases pose difficult design problems for engineers attempting to add additional components into the limited available space. For larger components, such as monitors, RAID disk arrays, or larger servers, the rack must be provided with taller openings, such as a 4U or 6U rack.
One type of server manufactured and sold by the assignee of this invention is the VArServer 700. The body of the VArServer 700 is provided with five hard drive bays into which half-height hard drives can be mounted to form a RAID array. Hard drives sold by different manufacturers are typically provided in standard sizes, thus allowing the hard drives from different manufacturers to be used interchangeably. Half-height hard drives are 1.625xe2x80x3 tall and are often chosen for server systems because of their increased storage capacity (up to 36 GB, at the time of this application""s filing). The drives in the VArServer 700 are mounted in two stacks of two drives, plus a single drive. Because of the size of the array of hard drives and the thickness of the drives and the related mounting structure, the server requires a tall 4U chassis.
Another type of server manufactured and sold by the assignee of this invention is the VArServer 500. The VArServer 500 has a compact 2U form factor, which limits the size of the hard drives its chassis can accommodate. Because of its limited size, the VArServer 500 may utilize xe2x80x9clow profilexe2x80x9d drives, which are approximately 1.0xe2x80x3 high, rather than the half-height drives preferred in server systems.
It is also known to mount different size drives in a single case. In one type of system, a low profile drive is mounted on top of a half-height drive in a 2U case. Although this provides increased storage capacity over a system using only low profile drives, a disadvantage of this system is that the low profile and half-height drives cannot be used interchangeably. In particular, this limits the type of xe2x80x9chot swappingxe2x80x9d that can be used for this server.
Hard drives are not the only system components that create challenges for design engineers. High-end computer systems may utilize numerous expansion cards, such as video accelerators or network cards. These cards plug into expansion slots using various methods well known in the art. These cards are referred to as xe2x80x9cPCI cards,xe2x80x9d because they often operate in conjunction with a PCI bus on a computer. As the number of components increase, while the amount of available space inside the server case decreases, providing secure mounts and expansion slots for such cards poses a significant problem.
Another limiting factor with high-end computing systems is ensuring effective heat dissipation from the various hardware components. In particular, the central processing unit and the electrical components mounted on the various circuit boards in the computer system generate large amounts of heat. Without proper cooling, these components can fail or can cause other components mechanisms to fail. One conventional method of cooling these components is the use of a fan mounted on a side of the chassis to force air to flow from outside the chassis into and over the circuit boards. In a given chassis, this method is effective when the number and size of the components to be cooled are small. However, as more and more components are squeezed into smaller server cases, it becomes increasingly difficult to create an effective airflow. In addition, these additional components increase the overall cooling requirements of the system.
In accordance with the present invention, a computer system with densely-mounted components and effective cooling is provided. In one embodiment, a hard drive mounting structure for xe2x80x9chot swapxe2x80x9d hard drives utilizes a hard drive assembly in which a hard drive is mounted between a pair of parallel rails connected by a retaining portion. The rails provide a precise mechanism for loading and unloading the xe2x80x9chot swapxe2x80x9d drive, without increasing the overall height of each hard drive assembly. A handle with double-cam actuation is used during insertion and removal of the hard drive assembly. In accordance with the present invention, two half-height hard drives may be stacked in a server mountable in a 2U rack.
A computer system for highly dense mounting of components is provided, wherein the computer system comprises a case including a drive bay and a drive assembly removably mounted in the first drive bay, wherein the drive assembly of the computer system comprises a hard drive and a hard drive chassis. The hard drive chassis comprises a first rail provided along a first side of the hard drive; a second rail substantially parallel to the first rail and provided along a second side of the hard drive opposite the first side; and a retaining portion adjacent a front side of the hard drive and connecting a front end of the first rail to a front end of the second rail; wherein the top and bottom portions of the hard drive are not covered by the hard drive chassis.
In another aspect of the present invention, a first notch is provided on a first interior side of the first drive bay; a shoulder is provided on a second interior side of the first drive bay opposite the first interior side; a handle is rotatably connected to the retaining portion of the first drive chassis and has a first end and a second end distal from the first end. The handle is rotatable about an axis located between the first and second ends of the handle. The handle defines a closed position in which the first end of said handle is a first distance from the front end of the first rail of the first drive assembly, and defines an open position in which the handle is rotated about the axis such that the first end of the handle is a second distance from the front end of the first rail of the first drive assembly, the first distance being less than the second distance. A first latch is provided on the first end of the handle and adapted to engage the first notch when the first drive assembly is inserted into the first drive bay and the handle is in the closed position; and a cam is provided at the second end of the handle and adapted to abut the shoulder when the first drive assembly is inserted into the first drive bay.
In another aspect of the present invention, a clip for retaining expansion boards is provided, wherein the retaining clip comprises a clip body; a stabilizing projection attached to a top portion of the clip body, adapted to be mounted on a computer case such that said stabilizing projection is positioned on an exterior of the case and the clip body is positioned on an interior of the case; and a first flange attached to a side of the clip body and adapted to abut a first expansion board, thereby preventing horizontal movement of the first expansion board.